Ensure your computer meets the minimum system requirements for CATIA V5R20, especially since it supports both 32-bit and 64-bit architectures.
If you must use V5R20, ensure you are on a system with a certified OpenGL graphics card, at least 8 GB of RAM, and a legitimate license from an authorized reseller. For everyone else, treat this release as an artifact of engineering history—respected, but largely superseded. dss catia p2 v5r20 ga sp0 win32 win64 multi
The installer hangs on Windows 10/11.